1. a QSS Group Inc., 4500 Forbes Blvd, Lanham, MD 20706, USA and Office of Research and Applications, National Environmental Satellite , Data and Information Service, NOAA , Camp Springs, MD 20746, USA
2. b Geophysical Institute , University of Alaska Fairbanks , Fairbanks, AK 99775, USA
3. c Steven Institute of Technology , Hoboken, NJ 07030, USA
4. d Scripps Institution of Oceanography , University of California , La Jolla, CA 92093, USA